It’s a balancing act that Rubio and other potential 2016 presidential candidates must master if they’re going to go anywhere. Social issues like abortion can certainly fire up legions of small donors, but staying away from those issues helps appeal to a larger pool of megadonors focused on economic issues. And it’s the big money that funds the super PACs and nonprofits that can swing elections.

Rubio has already seen the benefits from his efforts on immigration reform, which has huge support among the GOP big donor class. Between April and June, when the immigration bill was debated in the Senate, he raised $3 million, 30 percent more than the previous quarter, his campaign finance filings are expected to show.

After the GOP’s dismal national performance last year, major donors have repeatedly pushed Republicans to stick to economic issues, and several high-profile establishment figures like Grover Norquist and Jeb Bush have touted the economic argument for an immigration bill. But Republicans have continued to draw headlines for efforts to limit abortions in several states including Texas, giving Democrats plenty of fodder to feed the “war on women” narrative and boost their own fundraising.

“Donors are investors. They’re investing in something they believe in and expect a return on investment. That return on investment is that they want to win,” said Brad Blakeman, a member of former President George W. Bush’s senior staff. Blakeman also founded Freedom Watch, a nonprofit largely funded by casino mogul Sheldon Adelson.

“They’re looking at the poll numbers and seeing what the American people have on their minds, and that’s the economy,” Blakeman added. “Introducing issues that have no signs of passage is an exercise in futility.”

Rubio has not decided whether he will sponsor the 20-week measure, but he told POLITICO he is “very supportive” of it and has been discussing the issue with other senators.

“It’s definitely going to be a balancing act,” a top national finance consultant said in an interview. “The 20-week abortion legislation will definitely galvanize the small-dollar donors, especially the direct mail folks. If you’re Rubio and you’re looking to reposition yourself and looking to galvanize the base, it’s a smart move.